It's an aromatase inhibitor so it prevents the conversion of testosterone to estrogen so you won't get bloat and gyno. If you prefer you can go with aromasin or arimidex instead but AIFM is the least expensive way to go.
You gains will depend on a lot of factors; your diet especially. But test/deca/d-bol is the classic bulking stack. 20 lbs of gain would not be impossible.
Yes you're better off just using AIFM for the cycle and PCT.
I agree to switch from sust if you can. Use Prop or enanthate, preferably Prop. 3 weeks of drol is enough, I would use the dbol instead for 3 weeks. I'd like to be the first to congratulate you on making a 7 week cycle. Odd numbers of weeks are rarely seen around here.
Now you tell me that HAD to go 7 weeks because that's all you had.
comes in a spray bottle so you just spray it on a vascular area and rub it in....instructions on the site. and prop would be alot better for a 7 weeker